1. Field
The present invention relates to a drain device and a washing machine having the same, and more particularly, to a drain device having a filter to filter out foreign substances from washing water during a draining operation and a washing machine having the same.
2. Description of the Related Art
Generally, washing machines are divided into pulsator washing machines, which wash laundry by rotating washing water and the laundry using a pulsator rotatably installed on the bottom of an inside of a tub, agitator washing machines, which wash laundry by agitating washing water and the laundry using an agitator protruded from a central region of the inside of the tub, and drum washing machines, which wash laundry by repeatedly lifting and dropping the laundry through the rotation of a drum accommodating the laundry. Recently, the drum-type washing machines, which have excellent washing power, use a small amount of water, and scarcely damage laundry, are increasingly in demand.
Each of the above various washing machines includes a drain device to discharge washing water from a washing chamber to the outside in a dehydrating operation. Generally, a drain device includes a drain case having a filter chamber to filter out foreign substances coming apart from laundry, such as hairs and nap, from washing water and a pump chamber to forcibly discharge the washing water, an internal drain hose guiding the washing water in the washing chamber to the drain case, an external drain hose guiding the washing water in the drain case to the outside of the washing machine, and a drain valve installed in the internal drain hose.
Korean Patent Application No. 10-2002-0027826 (Publication No. 10-2003-89913) discloses a drain device. The drain device disclosed in the above Application is installed such that a front part of a drain case is connected to a mounting hole formed in a front surface of a housing of a washing machine and a drain pump is exposed forwardly from the housing. Washing water flowing into the drain case is filtered via a filter portion, and is discharged to the outside by a high-speed rotation of an impeller via a pump chamber.
In the above conventional drain filter, a channel pipe having a hollow cylindrical shape is installed at a central portion of a filtering plate to filter out foreign substances. Therefore, large foreign substances, such as coins and buttons, can be effectively filtered by the filter portion, but smaller foreign substances, such as toothpicks and hairpins, cannot be completely filtered out by the filter portion and may flow into the pump chamber, thereby generating restriction and breakage of the impeller, and thus causing poor draining and malfunction of the pump.
Further, Korean Patent Registration No. 0441095 discloses a pump unit of a washing machine, in which a drain filter having a plurality of through-holes formed in a mesh shape is installed in a filter chamber. In the same manner as the earlier conventional drain filter, this drain filter of the pump unit can effectively filter out large foreign substances, but the foreign substances are accumulated around the through-holes at a high speed and thus the amount of drained washing water is reduced in a short time, thereby causing a user to frequently clean the drain filter.
Further, in each of the above conventional drain devices, since the washing water flows into the conventional drain device through a side surface of the drain case, in the case that foreign substances having a bar shape, such as candy sticks, toothpicks, and hairpins, flow into the filter chamber, the foreign substances are accumulated rapidly, and the drain filter cannot be easily attached to and detached from the pump unit.